It's an interesting point you bring up about senescence in general. I think there is an idea today that you shouldn't expect to live forever. Taking this view,

It's an interesting point you bring up about senescence in general. I think there is an idea today that you shouldn't expect to live forever. Taking this view, it could add another factor to the problem of how to spend a health budget. For example, an argument could be made under this view that preventing cancer in children would be more important than curing Alzheimer's, even if it is less common. Lastly, the claim that "we only spend x amount on y disease" is flawed. Alzheimer's is an extremely complex disease because it has to do with the degeneration of the neurons in our brain. Our understanding of the brain is still limited, which means we likely need to understand the brain more in general in order to understand Alzheimer's disease, which is a special case of brain function in general. That being the case, I think a lot neurological research is helping Alzheimer's in some way, even if it is not labeled as such. To give the most extreme and obvious example, the discovery of neurons itself can be considered research of Alzheimer's, even though the researchers had no such intention. Taking this view further, we can consider research in ancillary fields like gene sequencing to be aiding in Alzheimer's research. It may be something that comes down to fully or almost fully mapping out the brain and the functions of all its relevant genes in order to solve the problem. I doubt such as massive undertaking would labeled as "Alzheimer's research."